Flexible abrasive articles are useful for removing a small amount of material from the surface of a workpiece (or substrate). This is commonly done to make the surface smoother, but such abrasives can also be intended to remove a layer of old material from a surface or even impart greater roughness to a surface in preparation for a repair.
Such abrasive articles are constructed by adhering abrasive particles to a flexible backing, such as paper, to form a coated abrasive. Sandpaper is a prime example. These sheet-like abrasives can be grasped by the hand or fastened to a sanding block and frictionally translated across the surface to be finished. Alternatively, the abrasive can be fastened to a reusable backup pad mounted to a disk sander, random orbital sander, or other power tool for rapid surface finishing. In these cases, the abrasive article typically incorporates some sort of attachment interface layer such as a hooked film, looped fabric, or adhesive for coupling to the backup pad.
In many applications, the flexible abrasive article is used with water or some other liquid, optionally containing a surfactant, which acts to lubricate and remove swarf and debris from the abrading surfaces. The liquid applied at the interface can reduce heat build-up and, in some cases, even be used to impart a surface treatment to the finished substrate.
Two problems are known to arise when performing a wet sanding operation. The first is known as “stiction,” a phenomenon where the damp abrasive tends to bind and “stick” to the workpiece as a result of surface tension. Stiction can result in loss of user control over the abrading operation and consequent damage to the workpiece. The second is hydroplaning, which occurs when the abrasive and workpiece become separated by a thin layer of the liquid. This can cause the abrasive to skid across the surface without directly contacting the workpiece, degrading cut performance.